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Immunotherapy with BCG is an effective and widely used treatment for non-muscle-invasive bladder cancer. BCG sepsis is a rare but life-threatening and frequently not a straightforward complication of this treatment; in cases with a high index of suspicion, anti-bacillary treatment should not wait for laboratory confirmation and be instituted immediately. We report a severe case of BCG sepsis, in which timely diagnosis and initiation of antituberculosis agents enabled a full recovery.

The applicability of two alternative spectroscopic techniques (i.e., 1H NMR and NIR) for the quantitative characterisation of gasoline was compared in this work. The chemometric approach followed t...

Submitted by Isabel Melo (imelo@sa.isel.pt) on 2020-02-13T12:28:34Z No. of bitstreams: 1 Effective_PLAlmeida.pdf: 2814345 bytes, checksum: 6bf343b065cf3469082d8961791ea3bf (MD5) Made available in DSpace on 2020-02-13T12:28:34Z (GMT). No. of bitstreams: 1 Effective_PLAlmeida.pdf: 2814345 bytes, checksum: 6bf343b065cf3469082d8961791ea3bf (MD5) Previous issue date: 2019-10-09 info:eu-repo/semantics/publishedVersion

A combination of catalytic oxidation and extraction was used for the desulfurization of a model diesel containing benzothiophene, dibenzothiophene and 4,6-dimethyldibenzothiophene, or a real diesel sample with a sulfur content of 2300 ppm. The catalysts used were the soluble peroxo compound (nBu4N)3{PO4[WO(O2)2]4} (PW4) and a supported material denoted as PW4@TMA-SBA-15 that was prepared by immobilization of PW4 in an ordered mesoporous silica (SBA-15) derivatized with propyltrimethylammonium groups (TMA). The supported catalyst was characterized by FT-IR, FT-Raman, 31P and 13C MAS NMR spectroscopies, powder X-ray diffraction and scanning electron microscopy. Under optimized conditions (H2O2/S molar ratio = 7, 70 °C, acetonitrile as extraction solvent), both catalysts led to complete desulfurization of the model diesel within a reaction time of 2 h. The desulfurization systems could be recycled 10 times with only a slight decrease in performance being observed between the 9th and 10th oxidative desulfurization cycles. Application of the PW4 system to the real diesel led to an outstanding desulfurization efficiency of 89% after a reaction time of 2 h.

Oxidative desulfurization (ODS) is a method of removing sulfur from diesel fuel that has the potential to complement or even replace conventional hydrodesulfurization processes in oil refineries. One of the most promising variants of ODS is extractive and catalytic ODS (ECODS) in which the organic sulfur compounds in the liquid fuel are oxidized and extracted in situ from the oil phase into an extractant phase. In this study, the desulfurizalion of model and real diesel fuel has been performed in ECODS systems employing two different types of deep eutectic solvents (DESs), prepared by combining polyethylene glycol (PEG) as hydrogen bond donor with tetrabutylammonium chloride (TBACl) or choline chloride (ChCl) as hydrogen bond acceptor. The ECODS systems were evaluated with the complexes [MoO2Cl2(DMB)(2)] (1) and [MoO2Cl2(DEO)] (2) (DMB - N,N-dimethylbenzamide, DEO = N,N'-diethyloxamide) as catalysts and 30 wt% H2O2 as oxidant. The effects of different reaction conditions, such as the amount of catalyst, H2O2 and DES, and reaction temperature, were investigated. The combination of complex 1 with the DES ChCl/PEG showed the best performance for the removal of dibenzothiophene, 4-methyldibenzothiophene and 4,6-di methyldibenzothiophene from a high-sulfur (3000 ppm) model diesel, allowing a desulfurization efficiency of 99.6% to be attained at 70 degrees C within 2 h. By applying the optimized model diesel ECODS systems to the treatment of a commercial untreated diesel with a sulfur content of 2300 ppm. 82% of sulfur compounds could be eliminated. These promising results indicate that DESs are a viable alternative to ionic liquids as extraction solvents in ECODS processes. (C) 2020 Elsevier B.V. All rights reserved. project REQUIMTE-LAQV [FCT (Fundacao para a Ciencia e a Tecnologia)] [UID/QUI/50006/2019] project CICECO-Aveiro Institute of Materials - Foundation for Science and Technology/MCTES [UIDB/50011/2020, UIDP/50011/2020] FCTPortuguese Foundation for Science and TechnologyEuropean Commission [SFRH/BD/102783/2014] European UnionEuropean Commission [SFRH/BD/102783/2014] MCTES European Social Fund through the program POPH of QREN info:eu-repo/semantics/publishedVersion

Highly efficient, deep desulfurization of a multi-component model diesel containing benzothiophene (BT), dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) has been achieved by using the peroxophosphomolybdate [(n-C4H9)4N]3{PO4[MoO(O2)2]4} (Q3PMo4) directly as catalyst, and aqueous H2O2 as oxidant. Q3PMo4 behaves as a heterogeneous catalyst in the complete oxidation of the various sulfur compounds to the corresponding sulfones within 3 h at 70 °C, using a relatively low H2O2/S molar ratio of 3.7, and could be recycled for ten times with only a minimal decrease in activity. A study was performed to adapt the catalyst Q3PMo4 for the removal of sulfur from a real untreated diesel while maintaining a low, economically desirable, H2O2/S molar ratio of 3.7. The highest desulfurization performance was achieved in the presence of an extraction solvent during the catalytic oxidative stage, reinforced by two extraction steps before and after sulfur oxidation. Under these conditions, the sulfur content of the real diesel was reduced from 2300 to 500 ppm (78% desulfurization efficiency) after 3 h.

A novel composite has been prepared through the immobilization of the Keggin sandwich-type [Sm(PMo11O39)2]11− anion (SmPOM) on large-pore silica spheres previously functionalized with trimethylammonium groups (TMA). The resulting SmPOM@TMA-LPMS material has been evaluated as heterogeneous catalyst in a biphasic desulfurization 1:1 diesel/extraction solvent system using H2O2 as oxidant. Preliminary experiments were conducted with different extraction solvents, acetonitrile and [BMIM]PF6 ionic liquid. The optimized extractive and catalytic oxidative desulfurization system (ECODS) with [BMIM]PF6 was able to reach complete sulfur removal from a model diesel containing 2100 ppm S in just 60 min (10 min of initial extraction + 50 min of catalytic step). The reutilization of catalyst and extraction phase has been successfully performed without loss of desulfurization efficiency in consecutive cycles, turning the process more sustainable and cost-effective. The remarkable results with simulated diesel have motivated the application of the catalyst in the desulfurization of untreated real diesel and 74% of efficiency was achieved after only 2 h for three consecutive cycles.

The physicochemical properties of the crude oils can vary significantly, depending on their sources. While cheaper crude oils are desirable, the selection and blending operations should also take into consideration the potential operational problems on the downstream processing units. Cluster analysis is a data science technique that groups observations based on their similarity. By clustering crude oils based on their properties, it is expected that observations within a cluster will present similar behavior in the refining process. In this work, a data set from Galp’s refineries containing 418 observations, with 9 properties, from 38 different sources was used. K-means clustering was applied after preprocessing and good results were obtained by selecting both 3 and 8 clusters, with only 0.7% and 3.7%, respectively, being placed in different clusters than the one with the highest family representation. This method also identified some observations with abnormal properties such as iron content. These results show the potential of grouping crudes based on their properties and the capability of finding potential outliers. This work allows the refineries to know how similar different sources are, potentially improving the task of formulating crude oil blends.

Efficient and recyclable liquid–liquid extraction and catalytic oxidative desulfurization (ECODS) systems for the removal of refractory sulfur compounds from liquid fuels are reported that use the cyclopentadienyl molybdenum tricarbonyl complexes [CpMo(CO)3Me] (1), [CpMo(CO)3(CH2-pC6H4-CO2Me] (2) and [CpMo(CO)3CH2COOH] (3) as catalyst precursors. An ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was used as both extractant and reaction medium, entrapping the active homogeneous MoVI catalysts that are formed in situ under the operating catalytic conditions (aqueous H2O2 as oxidant, 50 °C). The high sulfoxidation activity of the catalyst formed from 1 was largely responsible for enabling >99% desulfurization within 1 h of a model oil containing 1-benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene (2000 ppm S). The IL/catalyst phase could be repeatedly recycled with no loss of desulfurization efficiency. By sequentially performing extractive desulfurization and ECODS steps, 83–84% sulfur removal was achieved for untreated real diesel and jet fuel samples with initial sulfur contents of ca. 2300 and 1100 ppm, respectively.

This work addresses the preparation of bitumen blends using asphaltic residue, vacuum residue, and three aromatic extracts (by-products) from the refining process of base oils. A constrained mixture design was adopted to guide bitumen formulation. The measured responses were fitted to Scheffe polynomial models, namely a quadratic model for the penetration value and a linear model for the softening point. Both models were validated using ANOVA. In a second stage the quadratic model was used to design formulations with a precise penetration value. The predicted and measured responses demonstrate the accuracy of both models with average deviations of only 4.67% and 1.53% for penetration and softening point, respectively. In the whole, mixture design has been shown to be a successful and essential tool for bitumen formulation especially if the blends involve a large number of components.

TUD-1 type mesoporous aluminosilicates were explored for the acid-catalysed oligomerisation of 1-butene, under high pressure, continuous flow operation, which is an attractive route to produce sulphur-free synthetic fuels with reduced aromatics content. The solid acid catalysts were synthesised via one-pot synthesis (HT) or stepwise approach (PG), without using surfactants as templates, which is an eco-friendly characteristic of the TUD-1 family. While the HT approach may be advantageous in terms of process intensification in relation to the PG one, the latter may lead to relatively low molar ratios Si/Al. The catalysts possessed Si/Al ratios in the range 3–5 and 17–35 for the PG and HT approaches, respectively, pore sizes in the range 10–14 nm, and essentially Lewis acidity. To the best of our knowledge, this is the first report of siliceous oxide TUD-1 furnished with acidity via post-synthesis grafting (PG) of Al-species. For comparative studies, an ordered mesoporous aluminosilicate was synthesised via the PG approach using surfactant mixtures. All materials prepared promoted the reaction of 1-butene to higher molar mass products. The best-performing catalyst in terms of space-time yields of the 170–390 °C cut (boiling point range) products (of the type middle distillates) was Al-TUD-1(25)-HT synthesised via the HT method. The products were analysed by comprehensive two-dimensional gas chromatography (GC × GC) combined with time-of-flight mass spectrometry (ToFMS). The influence of material properties and process parameters on the catalytic reaction, and catalyst stability were studied. The catalytic performances were benchmarked with ZSM-5 (zeolite used in commercial oligomerisation processes).

This work presents a successful recycling system based in homogeneous polyoxometalate catalysts to desulfurize model and real diesels. Various Keggin-type polyoxometates entrapped in a room temperature ionic liquid (RTIL) phase were investigated. The desulfurization process here proposed conciliates efficiently an extraction and an oxidative catalytic process under sustainable and moderate conditions (H2O2 as oxidant, 50 °C). The ionic liquid acts as an extraction solvent and also as an effective immobilization medium for the active homogeneous catalysts. The zinc-polyoxometalates presented high stability and high capacity to be recycled for various consecutive cycles with no loss of desulfurization efficiency. Complete desulfurization of model diesel was achieved at short reaction time (3 h). Under the same experimental conditions, 80% of sulfur was removed from real diesel (Sinitial = 2300 ppm).

The complexes [MoO2Cl2(DMB)(2)] (1) and [MoO2Cl2(DEO)] (2) (DMB = N,N-dimethylbenzamide, DEO = N,N'-diethyloxamide) have been evaluated as catalysts in extractive-catalytic oxidative desulfurization (ECOD) of a simulated diesel fuel. Using the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM]PF6) as extraction solvent and H2O2 as oxidant, ultra-deep desulfurization (S-content from 3000 ppm to < 10 ppm) was possible within a reaction time of 1-3 h, and the systems Catalyst/[BMIM]PF6 could be recycled for five times without significant decrease in activity. The S-content of a real untreated diesel was lowered by 94.4% from 2300 ppm to 129 ppm after only 2 h of reaction using the ECOD process with 2 as catalyst. REQUIMTE-LAQV [FCT (Fundacao para a Ciencia e a Tecnologia)] [UID/QUI/50006/2019] CICECO - Aveiro Institute of Materials (FCT) [UID/CTM/50011/2019] Centre of Marine Sciences - CCMAR [UID/Multi/04326/2019] FCT/MCTESPortuguese Foundation for Science and Technology FCTPortuguese Foundation for Science and Technology [SFRH/BD/102783/2014] European UnionEuropean Union (EU) [SFRH/BD/102783/2014] MCTES European Social Fund through the program POPH of QREN FCT, I.P.

The zinc-substituted polyoxotungstate [PW11Zn(H2O)O-39](5-) (PW11Zn) has been encapsulated within the aluminium(III) 2-aminoterephthalate NH2-MIL-101(Al) metal-organic framework (MOF) either directly through a one-pot microwave-assisted synthesis or by an impregnation method. The resultant composite materials were characterized by elemental analysis, powder X-ray diffraction, FTIR spectroscopy, and P-31 magic-angle spinning (MAS) NMR spectroscopy. The desulfurization of a model diesel containing three refractory organosulfur compounds (1-benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene) was studied with the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate as an extractant, the PW11Zn@MOF composites as sulfoxidation catalysts, and aqueous H2O2 as an oxidant. The composite obtained by direct synthesis was the most efficient catalyst and led to almost complete desulfurization of the model diesel under mild conditions. Moreover, the solid catalyst could be recovered readily and recycled without significant loss of desulfurization performance. The application of this system to the treatment of a real diesel sample provided a very good sulfur removal of 83% when combined with liquid-liquid extraction.

The study of the phase behaviour of binary mixtures of fatty acid methyl esters (FAME) and alkanes are here studied to understand the behaviour of the mineral diesel/biodiesel blends. Six binary mixtures of the most common saturated methyl esters (methyl stearate or methyl palmitate) with a saturated alkane (hexadecane, octadecane or eicosane) were evaluated by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and optical microscopy. The binary mixtures studied show a more complex phase behaviour than previously reported, which it is shown to be dependent of the size difference between the alkyl chain length of the esters and the alkanes. It was found that in mixtures with equal alkyl chain length a co-crystal is formed, and when the alkane chain length is larger than in the FAME by two methylene groups the formation of a solid-solution increasing significantly the solid phase stability is observed. The results and conclusions derived from the phase behaviour of this set of binary mixtures, between alkanes and methyl esters, can be used as a model for the interpretation of the cloud and pour points increase in biodiesel blends (in special the ones with a rich fraction of methyl palmitate or methyl stearate when combined with mineral diesel with high content of octadecane or eicosane respectively).

This work focuses on the prediction of research and motor octane numbers of gasolines throughout multivariate statistical analysis, which may significantly increase the celerity of the quality control process. The aim of this work is to compare the performance of two different multivariate models, based on partial least squares regression and artificial networks. The results show that both models predict octane numbers with accuracy, presenting coefficients of determination above 0.95 for the calibration data set. For the test data set, partial least squares model is more accurate, which might indicate the existence of linear correlations between spectral data and octane numbers. The statistical parameters also show that the research octane number prediction is more accurate than the motor octane number.

This work proposes an alternative technique for the selective extraction of thiols from a \"jet-fuel\" model stream, using the 1-ethyl-3-methylimidazolium triflate ([C(2)mim][CF3SO3]) ionic liquid as extractant, in a hollow fibre membrane contactor. Due to the low distribution ratio of the thiol towards the ionic liquid, observed in single extraction, a regeneration step (stripping with vacuum or a sweep gas) was added to the extraction process, in order to maximize the concentration gradient overcoming thermodynamic constraints. The stripping with a sweep gas allowed for a complete regeneration of the ionic liquid producing a jet-fuel with sulphur content lower than 2 ppm. Since the controlling step of the process is the extraction of thiol from the feed phase to the ionic liquid phase, the increase of the ionic liquid velocity and operating temperature may further enhance the process performance. The results obtained along with the ultra-low sulphur jet-fuel model produced prove the high potential of this integrated process as an alternative method for replacing the current expensive desulphurization process. (C) 2014 Elsevier B.V. All rights reserved.

Made available in DSpace on 2017-12-07T19:57:45Z (GMT). No. of bitstreams: 2 license.txt: 2154 bytes, checksum: 4b0f01eb19f34a0ae8b22225f6f5120c (MD5) Production of ultra-deep sulfur-free diesels using a sustainable catalytic system based on UiO-66(Zr)_10.1039c5cc03958d.pdf: 1011820 bytes, checksum: a1f67332efe0f7ec4a768d545adbf211 (MD5) Previous issue date: 2015

The desulfurization efficiency of various hybrid zinc-substituted polyoxometalates ([PW11Zn(H2O)O39]5−, abbreviated as PW11Zn) was here investigated for the first time and optimized using sustainable systems conciliating successfully the liquid–liquid extraction and the oxidative catalytic process. Initially, the desulfurization studies were performed using a model diesel containing a mixture of the most refractory sulfur compounds and later extended to an untreated real diesel. In both cases, acetonitrile was used as extraction solvent and aqueous H2O2 as oxidant. High level of desulfurization was achieved using model and untreated diesels after few hours. The quaternary ammonium catalysts (TBAPW11Zn and ODAPW11Zn) showed higher catalytic desulfurization efficiency than the ionic liquid catalyst (BMIPW11Zn). The TBAPW11Zn behaved as a homogeneous catalyst immobilized in the extraction solvent, while the ODAPW11Zn with the long carbon chain behaved as a heterogeneous catalyst capable to be recovered from the system. Both quaternary ammonium catalysts showed to be successfully reused/recycled for various consecutive desulfurization cycles.

Submitted by Bella Nolasco (bellanolasco@ua.pt) on 2017-07-26T16:06:19Z No. of bitstreams: 1 A recyclable ionic liquid-oxomolybdenum(VI) catalytic system for the oxidative desulfurization of model and real diesel fuel_10.1039c6dt02065h.pdf: 692592 bytes, checksum: 896be0ecee91d017b0677172ee92729a (MD5) Approved for entry into archive by Bella Nolasco(bellanolasco@ua.pt) on 2017-07-26T16:06:45Z (GMT) No. of bitstreams: 1 A recyclable ionic liquid-oxomolybdenum(VI) catalytic system for the oxidative desulfurization of model and real diesel fuel_10.1039c6dt02065h.pdf: 692592 bytes, checksum: 896be0ecee91d017b0677172ee92729a (MD5) Made available in DSpace on 2017-07-26T16:06:45Z (GMT). No. of bitstreams: 1 A recyclable ionic liquid-oxomolybdenum(VI) catalytic system for the oxidative desulfurization of model and real diesel fuel_10.1039c6dt02065h.pdf: 692592 bytes, checksum: 896be0ecee91d017b0677172ee92729a (MD5) Previous issue date: 2016-08

Over the recent years, bitumen modification with polymers, acids, or mineral fillers has gained relevance to adjust its performance properties. This work reports the use of polyphosphoric acid (PPA) for the modification of formulated bitumen. With this objective, an in-depth literature review on PPA modification was firstly performed. Subsequently, five individual refinery components were selected for the preparation of bitumen blends, namely, asphaltic residue, vacuum residue, and three lube oils extracts. Seven binary/ternary bitumen blends were prepared and then treated with PPA. Afterwards, the five components and the unmodified and PPA-modified bitumen were characterized by standard methods (penetration, softening point, and penetration index), SARA analysis, elemental analysis, and31P and1H nuclear magnetic resonance (NMR) spectroscopy. The results evidenced higher asphaltenes and lower saturates/resins contents in PPA-modified bitumen. The NMR data suggest that the paraffinic chains became longer, the content of condensed aromatics increased, more substituted aromatic structures appeared, andα-hydrogen in aromatic structures diminished. These findings disclosed the improved consistency and oxidation stability of PPA-modified bitumen blends.

Many separation processes in petrochemical and refining industries are applied to close boiling point compounds and/or azeotropic mixtures which make difficult the application of simple distillation, requiring alternative separation processes. Ionic liquids, with their unique and tunable properties, may constitute an advantageous alternative as extractive solvents in separation processes that involve hydrocarbon systems. In this work, a review on the experimental data available for ternary systems composed of ionic liquids and hydrocarbons is reported. The gathered information was shown to be essential in the understanding of the molecular interactions and of the effect of the various structural features of both the ionic liquids and the hydrocarbons on their phase behavior, allowing the development of guidelines for the choice of the most suitable ionic liquid for hydrocarbon separation. To be able to carry out the design and selection of new and improved ionic liquids, the development of predictive mode...

Ionic liquids (ILs), with their unique and tunable properties, are attracting the interest of both academia and refining companies as potential solvents for the extraction of specific compounds from hydrocarbons’ streams. For such a purpose, the knowledge of the mutual solubilities between ionic liquids and hydrocarbons is required. Experimental measurements for all these systems are impracticable due to the large number of possible combinations of ionic liquids and hydrocarbons. Thus, a deeper understanding of the interactions taking place, and ruling the phase behavior, and the development of predictive models are essential issues to forecast a general picture of the liquid−liquid equilibria (LLE) between ionic liquids and hydrocarbons. In this work an overview of the mutual solubilities between ionic liquids and hydrocarbons is presented. A review of the experimental data available is reported, and the effect of various structural features of both the ionic liquids and the hydrocarbons through their mu...

This work proposes an efficient desulfurization system to produce low sulfur diesel under sustainable and moderate experimental conditions. Treatment of a real diesel with a sulfur content of 2300 ppm led to 80% desulfurization after 2 h. The processes used conciliate liquid-liquid extraction and sulfur oxidative catalysis. The catalytic performance of the commercial Keggin-polyoxomolybdate H3[PMo12O40] (PMo12) was strategically increased by simple cation exchange, using a long carbon chain (ODAPMo12, ODA = CH3(CH2)17(CH3)3N), and by its incorporation into the Metal-Organic Framework (MOF) NH2-MIL-101(Cr), forming a new active heterogeneous PMo12@MOF composite catalyst. Activity of both catalysts was similar, however, the solid catalyst could be easily recovered and reused, and its stability was confirmed after multiple continuous cycles.

Renal sinus hemangiomas are extremely rare and little is known about these benign mesenchymal tumors. We report a case of a suspected complex renal cyst. Ultrasonography, computed tomography and magnetic resonance were unable to rule out malignancy. The patient underwent nephrectomy, and histology revealed a renal sinus hemangioma without relation to parenchyma. Based on this case we discuss this infrequent pathology.

No intuito de proporcionar a formação acadêmica ampla e de qualidade, o Programa de Educação Tutorial (PET) é um modelo indissociável de ensino, pesquisa e extensão, que preza também por valores de cidadania e consciência social. Apesar de existir desde a década de 90, com o nome de Programa Especial de Treinamento, e ter se expandido para mais de 37 grupos na área de Computação, pouca ou nenhuma literatura tem sido produzida com intuito de prover uma base metodológica de atuação desses grupos. Este artigo descreve métodos e práticas que têm sido utilizados com êxito pelo PET de Ciência da Computação da Universidade Federal do Maranhão (PETComp/ UFMA) no desenvolvimento de suas atividades, aprimorados ao longo de seus oito anos de existência.

Cloud and pour points are part of the specifications for diesel fuel oils. This work studies the dilution of a diesel with a jet fuel of very low cloud point to produce fuel blends with lower cold characteristics. It is shown that the cloud point of the blend is a highly non-linear combination of the cloud points of the original fuels and is mainly dependent on the cloud point of the heavier fluid. Using a thermodynamic model previously proposed, an accurate description of the cloud point for the fuel blends is achieved. This model also allows an estimation of the amount of solid at the pour point showing that as little as 0.5–1 wt% of solids are enough to gel the fuel.

Vaginal pessaries represent a valid therapeutic option for the management of female pelvic organ prolapse in elderly women with significant comorbidities. Although leading to good functional and quality of life outcomes, when neglected, they can cause significant and severe complications.1 An 87-year-old woman semidependent and uncooperative due to progressive Alzheimer’s dementia, who has lived in a nursing home for the last 5 years, presented to our outpatient clinic for ‘intermittent hematuria’. She carried a pelvic ultrasound documenting a ‘polypoid formation with 23 mm on the posterior bladder wall suggesting a bladder tumour’. The blood loss had …

Submitted by Gestor HospitalBraga (bibliotecaria@hospitaldebraga.com.pt) on 2015-03-30T21:17:02Z No. of bitstreams: 1 Peristomal struvite incrustations.pdf: 259814 bytes, checksum: 1517a93e259777db76207b2b7c477a14 (MD5) Approved for entry into archive by Gestor HospitalBraga (bibliotecaria@hospitaldebraga.com.pt) on 2015-03-30T21:17:22Z (GMT) No. of bitstreams: 1 Peristomal struvite incrustations.pdf: 259814 bytes, checksum: 1517a93e259777db76207b2b7c477a14 (MD5) Made available in DSpace on 2015-03-30T21:17:22Z (GMT). No. of bitstreams: 1 Peristomal struvite incrustations.pdf: 259814 bytes, checksum: 1517a93e259777db76207b2b7c477a14 (MD5) Previous issue date: 2014

This work focuses on the use of ionic liquids as alternative solvents for the removal of thiols, at room-temperature, from n-dodecane used as jet fuel model stream. The model extraction system composed by a selected ionic liquid, the thiol to be removed and an alkane representative of the jet-fuel, show high selectivities and low distribution ratios, which makes unfeasible the use of conventional liquid-liquid extraction processes due to the high volume of ionic liquid required. This works evaluates the use of supported ionic liquid membranes (SILMs) for the selective removal of thiols applying vacuum in the downstream side. This approach consists in the incorporation of the ionic liquid inside the membrane pores, while due to the vacuum applied, the thiol compound is scrubbed. To study the target solute transport from the feed to the ionic liquid, extraction experiments were carried out using different 1-ethyl-3-methylimidazlium cation-based ionic liquids. The mass transfer resistance was found to be higher in the ionic liquid phase, which results mainly from the high ionic liquid viscosities, hindering the thiol transport. The SILMs stability was investigated by evaluating different membrane supports, with the various ionic liquids selected for study. The results obtained show that the ionic liquids were properly incorporated inside the pores of the membrane support. However, and despite the negligible mutual solubility between n-dodecane and the studied ionic liquids, n-dodecane permeation through the membrane support was found to be undesirably high. This problem was solved by using a membrane contactor with polypropylene hollow fibre membranes, not wetted by the ionic liquid, which receives the thiol compound transported. Under these conditions, n-dodecane was not detected in the receiving ionic liquid phase. (C) 2014 Elsevier B.V. All rights reserved.

Aiming at the replacement of the present inefficient and expensive desulfurization processes, ionic liquids have been considered as potential solvents to be used in extraction procedures. In this context, this work provides an experimental evaluation on the feasibility of ionic liquids for the selective extraction of a less studied class of aliphatic sulfur compounds - thiols. A mixture composed of n-dodecane and 1-hexanethiol was used, as a feed model of kerosene in \"jet-fuel'', and the tie-lines of the corresponding ternary systems were experimentally determined at 298.2 K and 313.2 K for imidazolium-and pyridinium-based ionic liquids. Using the experimental data, the selectivity and distribution ratios of 1-hexanethiol were also determined. Despite the small distribution ratios, these systems display a high selectivity meaning that the co-extraction of other fuel compounds can be controlled by the ionic liquids nature and/or chemical structural characteristics. The COnductor-like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium of the investigated systems. A good agreement between the experimental data and the COSMO-RS results was observed. Therefore, the extraction behavior with other ionic liquids not experimentally addressed was also predicted by COSMO-RS for the identification of the best potential candidates. The ionic liquids identified are constituted by a short alkyl side chain imidazolium, pyridinium and pyrrolidium cations, combined with the anions tosylate, diethylphosphate, ethylsulfate and triflate. (C) 2014 Elsevier Ltd. All rights reserved.

Alkaline incrusted cystitis is a rare chronic inflammatory disease characterized by bladder mucosal incrustations of inorganic salts. The genesis is conditioned by a pre-existing mucosal damage, urina

The state of the art in the characterization of heavy crude oil mixtures is presented. This characterization can be done by different techniques, such as gas chromatography (GC), high performance liquid chromatography (HPLC), thin layer chromatography (TLC), infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Nuclear magnetic resonance spectroscopy is the technique of choice due to its capability to provide information on the chemical nature of individual types of hydrogen and carbon atoms in different and complex mixtures of crude oils. The progress made in the interpretation of the NMR spectra with the development of new NMR techniques and different multivariate data analyses could give relevant information about the identification and characterization of hydrocarbons and their physical and chemical properties. These progresses can improve the refining industries operation as a result of the better knowledge on the crude composition that is fed in the refining process, as well as in the prediction of better operating conditions to obtain refined products with desired specifications and in quantities desirable to meet the market demands. The improvement in the refining operation conditions is reflected in economical benefits.

The standard ( p o = 0.1 MPa) molar enthalpy of combustion in oxygen at 298.15 K of liquid 3-methylpentane-2,4-dione (HMe acac ) was measured by static bomb calorimetry as −(3353.2±1.7) kJ · mol −1 . The standard molar enthalpy of formation of the crystalline copper(II) complex with 3-methylpentane-2,4-dione was determined, at the temperature 298.15 K, by solution-reaction calorimetry. The vapour pressures of the complex were measured as function of temperature by the Knudsen-effusion technique, and the standard molar enthalpy of sublimation Δ g cr H o m (396.70 K)/(kJ · mol −1 ) = 130.7 ± 1.0, was derived by the Clausius-Clapeyron equation. From this value, the standard molar enthalpy of sublimation was calculated as Δ g cr H o m (298.15 K)/(kJ · mol −1 ) = 135.6 ± 1.0. Measurement of the standard molar enthalpy of sublimation using a direct microcalorimetric method, confirmed the value from the Knudsen technique.

Objetivo: El infarto renal es raro y la presentación clínica inconstante causa dificultades diagnósticas. Aunque la mayoría de los infartos renales son causados por factores tromboembólicos obvios, algunos sólo se explican por una trombofília hereditaria o adquirida. Los autores presentan un caso de infarto renal segmentario asociado al factor V de Leiden. Método/Resultados: Varón de 48 años que presenta síntomas sugestivos de cólico nefrítico pero la resistencia a analgesia llevó a la realización de un TAC renal que reveló un infarto segmentario del riñón derecho. El estudio fue solamente positivo para el Factor V de Leiden. A pesar del diagnóstico y tratamiento se apreció atrofia del área renal afectada. Conclusiones: El infarto renal puede ser la presentación de una trombofília y ésta debería ser sospechada en la ausencia de factor embólico evidente. La utilización del TAC renal facilita el diagnóstico e inmediato tratamiento.